MY FCPX IS SUPER LAGGY. I WORKED 3H ON THIS PROJECT. PLEASE HELP ME !

Every time I playback on my timeline it lags when theres text on it.

the video runs very smoothly. But when I add text to hit...I start to lag every theres a text displayed. I tried to export it but it still lags.

I saw online that maybe I need to switch graphique cards settings but im on a old mackbook.

To be honest, I never had this problem before.

Select the text clip in your Timeline.
Use Control-Shift-R to render it.

Adding titles can make it slow down if it's an older/slower machine, and especially if the content is 4k H264.

Without knowing anything else about your machine or type of media, my best suggestion is use proxy mode.

You can transcode to proxy during import OR afterward by selecting the clips in the event browser, right-click, and picking "transcode media", then picking *only* "create proxy media". You don't need to pick "create optimized media".

Then click the drop-down triangle in the viewer at top right, and pick "proxy". This switches to the proxy media you just generated. Do all your editing but before final output, switch the viewer back to "optimized/original" or the output will only be in proxy resolution.

This will greatly improve your editing performance.

Ammine
Text can be processor intensive, especially if it has motion applied to it. The "Far far away" effect is especially hard on processor.
Another thing is what Font you use. If using a font that is not included in FCPX, especially some 3rd party fonts, this can also cause slow downs or even crashes, so check which font you are using and maybe try a different font.
Could also just be your system.

Hope this helps, Greg